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S Molliex

Publications and source records attributed to S Molliex.

23 records · Page 2Linked to original sources

Effects of intravenous midazolam on the work of breathing.

Midazolam at sedative doses induces an increase in upper airway resistance, but its effects on the work of breathing have not been established. The flow-resistive work of breathing and pulmonary resistance (RL) of eight healthy volunteers were measured, with either midazolam 0.1 mg/kg or placebo in a random order. Esophageal pressures were measured using a balloon-tipped catheter, airflow using a pneumotachograph. Total resistive work expressed per minute (WTOT) and per liter of ventilation (WTOT/VE), and their inspiratory (WI) and expiratory (WE) components were determined. No change was observed after placebo injection. Five minutes after midazolam injection, an increase was observed in WTOT (from 3 +/- 0.4 J/min [mean +/- SEM] at control to 6.3 +/- 1.1 J/min; P < 0.01) and in WTOT/VE (from 360 +/- 30 mJ/L at control to 1250 +/- 120 mJ/L; P < 0.01), involving both WI and WE components. An increased inspiratory RL was observed from 13.7 +/- 2.6 cm H2O.L-1.s-1 at control to 32.8 +/- 3.9 cm H2O.L-1.s-1 after midazolam. Changes in inspiratory RL were correlated to changes in WI and WI/VE (r = 0.574, P < 0.001; and r = 0.762, P < 0.001, respectively). Our results suggest that airway obstruction plays a major role in the increased work of breathing observed during sedation with midazolam.

Adult↗

[Neurotoxic role of glycocolle and derivatives in transurethral resection of the prostate].

72-year-old patient underwent an elective transurethral resection of the prostate (TURP) performed with a spinal anaesthesia. The irrigation solution contained glycine at a concentration of 15 g.l-1. The patient's level of consciousness deteriorated over the next 4 hours. He went in an areflexic coma with pupillary areflexia and left mydriasis. The diagnosis of TUR syndrome was substantiated by a sodium blood concentration of 98 mmol.l-1, an osmotic gap of 48 mosmol.kg-1 and blood ammonia at 415 mumol.l-1. To investigate the pathophysiological role of glycine and its metabolites, their concentrations were measured by chromatography and spectrometry in plasma and CSF 8, 24 and 48 hours postoperatively. Glycine and its metabolites (serine, alanine, glyoxylic acid and glycolic acid) accumulated during the postoperative period in both blood and CSF. The central nervous system is in direct contact with these neurotropic compounds. Glycine is an inhibitory neurotransmitter, whereas glyoxylic acid and glycolic acid are considered as to be neurotoxic.

Aged↗

Effects of midazolam on respiratory muscles in humans.

Midazolam at sedative doses alters the breathing pattern; however, its effects on respiratory load and respiratory muscle activity have not been established completely. Therefore, the effects of midazolam (0.1 mg/kg) on total pulmonary resistances and on diaphragmatic, intercostal, and abdominal muscle patterns were studied in nine volunteers. Measurements were performed during control, 5 and 10 min after midazolam, and then 2 min after 1.0 mg of intravenous flumazenil. After midazolam, total pulmonary resistance increased from 6.3 +/- 0.65 to 36.6 +/- 8.1 cm H2O-L-1 x s-1 (P < 0.01), a pattern associated with an increased intercostal electromyographic activity (peak and slope; P < 0.05). By contrast, the ratio of gastric pressure on esophageal pressure changes decreased from 65.5% +/- 6.2% to 16.3% +/- 3.9% (P < 0.01), indicating reduced diaphragmatic activity. In 7/9 subjects, there was expiratory abdominal muscle activity. Flumazenil reversed all these effects. We conclude that midazolam 0.1 mg/kg increases total pulmonary resistance and elicits a compensatory load response characterized by an increase in inspiratory intercostal and expiratory abdominal muscle activities whereas diaphragmatic contribution is reduced.

Abdominal Muscles↗